The plight of the Rohingya, more than a million mostly Muslim residents of Myanmar facing a government campaign of ethnic cleansing and torture, briefly dominated international headlines earlier this year. Then the world’s fickle attention drifted elsewhere. But the brutality the United Nations human rights chief has called a “textbook example of ethnic cleansing” continued.

On Friday, a group of celebrities made a bid to turn the spotlight back to the Rohingya ahead of a critical summit between the U.N. and the Association of Southeast Asian Nations that Myanmar’s de facto leader, Nobel Peace Prize winner Aung San Suu Kyu, is expected to attend.

“World leaders will gather at the Asean summit but the Rohingya crisis is nowhere on the agenda. We call on leaders to pressure the Myanmar government to stop these atrocities, grant the Rohingya citizenship, and allow them to return to a place they call home ... We must not be bystanders to this genocide. We cannot allow people to be slaughtered and burnt out of their homes, while the world watches,” reads a letter they signed and published in the Guardian. “After every atrocity, we say: ‘Never again.’ We must mean it.”

The message notes that Myanmar’s government has cited security concerns to drive out more than half of the country’s Rohingya population since Aug. 25, in many cases destroying the homes and land they leave behind. Despite Myanmar’s recent opening to the outside world, global figures have yet to convince its leaders to end the rampage, the letter adds; it suggests that foreign investors, who flocked to the country since that opening and generally maintain a conspicuous silence on the Rohingya, are complicit in the abuses. Facebook is the most prominent U.S. company facing those allegations because it has permitted ultranationalists to spew often false anti-Rohingya posts on its network for years.

The signatories to the Friday letter include Emmy winners Riz Ahmed and Aziz Ansari; comedians Mindy Kaling, Kumail Nanjiani and Hasan Minhaj; actors Frieda Pinto and Nandita Das; writers Salman Rushdie, Madhur Jaffrey, Kamila Shamsie, Karan Mahajan and Mohsin Hamid; and dozens of others from various fields. The vast majority were of South Asian descent, variously connected to Muslim, Hindu, Christian and other communities in the region; Bangladesh, the largely Muslim South Asian nation bordering Buddhist-majority Myanmar, is temporarily hosting many of the predominantly Muslim Rohingya despite its own strained resources.

International pressure on Myanmar has already grown significantly. On Monday, the U.N. Security Council approved its strongest statement against the country in nearly 10 years, and U.S. lawmakers are expected to vote before the end of the year on new proposed sanctions on Myanmar’s military.

But for now, it remains unclear when a change in government policy might come, and more than 610,000 Rohingya are stranded in camps in Bangladesh where malnutrition, disease and child trafficking are common, and hundreds more continue to arrive.